I was asking myself, and researched for a while on net, So what you think about next topic-issue: Whether the higher altitude (eg. above 500 metres) at wich the zoo is located, can negativelly affect biology of some animals who normaly originates from lowland areas, from low altitude. The atmospheric pressure at higher altitude is lower, that can cause lowered blood presure in both humans and animals. How the animals who evolved in lowland areas, or who were translocated from lowland areas to higher altitude, feels or how their systems work? Can that affect the breeding susscess. Also with the intensity of sun in some areas to animals who are from rainforest (protected from direct intense sunlight, eg. why there are blind malayan taprs in Australian zoos?) I researcehd on internet, and find that most very successfull and large zoos are located in lowland areas. Some exceptions were Hellabrunn zoo in Munich (altitude aroun 600 metres), or Madrid zoos (altitude around 630 metres)?